Chlorofluorocarbons (Freon or CFC's) have been recognized in recent years as a significant environmental problem. CFC's have been found to cause significant reductions in the stratospheric ozone layer, which functions to screen out significant amounts of the sun's deadly ultraviolet radiation. As the ozone layer is depleted, this screening is reduced and the ultraviolet radiation, which passes through the reduced layer, causes increased incidences of non-melanoma and melanoma skin cancer. In addition, CFC's also contribute to the greenhouse effect, since they are significantly more heat-absorbent than carbon dioxide. Other serious problems to the environment result from the release of CFC's into the atmosphere.
As a result of the scientific evidence linking the presence of CFC's in the atmosphere to the depletion of the ozone layer, laws (both federal and local) and regulations have been enacted which prescribe the conditions under which CFC coolants, which have been commonly used in freezers, refrigerators and automobile air conditioning systems, may be evacuated and discarded. In fact, in the United States and in other environmentally conscious countries, the production and use of CFC's is being phased out and prohibited. In the United States, there is a prohibition against venting withdrawn CFC coolants to the atmosphere, or against burying discarded cooling units in landfills without first removing the coolants contained in the units.
Various devices have been developed for facilitating the removal of CFC coolants from the refrigeration lines of air conditioners, refrigerators, freezers and the like by means of different types of piercing valves coupled through an evacuation line to a recovery vessel or bottle. It is important, from a standpoint of efficiency, to effect the removal of refrigerant fluids from the closed circuit lines of the assembled units in as short a time as possible. Typically, this is accomplished by piercing the refrigerant line on the unit from which coolant is to be recovered by means of a piercing valve, which then is connected to an approved storage vessel. The time required to secure such a piercing valve to the refrigerant line, to operate the valve, and then to subsequently remove the valve, can be significant. This substantially increases the cost of recovering the fluid from the discarded refrigeration unit.
Frequently, the removal of coolant from a discarded refrigeration device is accomplished by using a small saddle clamp with a piercing point and a coolant recovery line on it. The use of such devices require a high degree of manual dexterity. Several such clamps, involving various degrees of complexity in the manner in which they are sealingly secured to the refrigerant line and then subsequently operated, are disclosed in the U.S. Pats. to Lacart No. 2,875,777; Hogg No. 3,326,231; Wagner No. 3,428,075; Hogg No. 3,459,731; Langstroth No. 4,018,246 and Furmanek No. 5,025,633. While the piercing valve assemblies of these patents all differ in various constructional aspects, all of them involve a relatively large number of parts, and require considerable time and effort to install and use them.
An approach to significantly reduce the time required for the installation and removal of the piercing valve in order more efficiently to remove coolant from an existing refrigeration unit cooling line is disclosed in the U.S. Pats. to Hamel No. 3,395,724 and Tura No. 3,698,419. In both of these patents, a locking pliers is adapted to include a cradle on one of the jaws for receiving the refrigeration line which is to be purged. The other jaw carries a piercing needle and a resilient seal. The piercing needle is coupled to an evacuation hose; so that when the pliers are clamped onto a pipe, the piercing needle penetrates the pipe to permit evacuation of the pressurized fluid in the refrigeration or air conditioning system which is being evacuated. In both of these patents, a VICEGRIP type of pliers is employed.
A significant disadvantage of the piercing tools of both of these patents is that, in addition to the large number of parts required (including but not limited to all Of the parts commonly associated with VICEGRIP pliers), a substantial amount of space is required in two orthogonal directions to operate the tool. The pliers' handles must extend outwardly from the line or pipe which is to be pierced; so that they may be gripped and closed by the operator seeking to remove refrigerant from the line. The upper jaw in the devices of both of these patents then carries a piercing valve mechanism; and this mechanism extends upwardly from the jaw, which requires clearance in a direction perpendicular to the main direction of the handles of the pliers. Frequently, in refrigeration devices, especially refrigerators and freezers, the refrigerant lines are closely spaced together in loops or coils, which make access in this perpendicular or orthogonal direction difficult. As a consequence, while the devices of Hamel and Tura may appear to be easy to use and to facilitate refrigerant removal, they are instead difficult to use in close quarters. In fact, the tools of both of these patents are quite cumbersome to handle and operate.
It is desirable to provide a line evacuating device which overcomes the disadvantages of the prior art noted above, and which is inexpensive, simple in construction and use, and effective for the efficient removal of coolant from discarded refrigeration units.